1986 X-Tra cab 4x4 22R making "interrmittent machine" like grinding noise? For the life of me I can't tell where it's coming from! Definitely drivers side. It's intermittent and doesn't keep doing it long enough for me to stop and throw open the hood to find it. It seems to be triggered by a bump, and its not rpm related? A very loud 'Grrrrrrrrr' and then stops. Power steering pump? Steering gear box? It's baffeling the hell out of me! Thanks in advance!

 

Do You have to moving to hear the noise, or can you make it happen in the driveway?
Can I assume you’ve checked belt tension and p/s fluid levels?
i had a alternator make a wretched sound when the bearings failed, but it went downhill very fast.
you might grab the the fan blade and see if there’s excessive movement on the waterpump shaft.
thats about all I can think of with the info given so far.

 

Inspect the belts, accessories, and tensioner for wear and smoothness.

Growling belts are bad based on your description it's not the pump whirring.

 

I've had a number of idler pulley bearings on the alternator/water pump belt fail me. They usually will make that sound at first, especially when you accelerate the engine. Also, they do it more when everything is cold, and settle once things warm up.
My AC idler isn't used any more. I took the AC belt off when I moved from the never to be sufficiently despised Yuma Az up to Oregon. No real need for AC up here! And in an emergency, ie the water pump/alternator idler fails away from home, you can use the unused AC pulley for the water pump/alternator belt. Kinda handy...
If you have a loose belt, or damaged, they can also make strange noises like that. Up until they break on you, anyway. Not good if the engine's running hard. No water pump = real hot engine real fast. Hard on heads, head gaskets, and so on.

Good luck to you!
Pat☺

 

Luckily the alternator is driven by the same belt as the water pump, so if the belt fails, the alternator will also stop spinning, and the CHARGE light should come on. At least that is the theory.

 

Could be wheel bearings. Is it only when your moving or when idling as well? Worn bearings makes a pretty wretched grinding noise, and being triggered by bumps and not rpm related makes me think more suspension/wheel than engine bay

 

Yes only when I'm moving. Belt tension and fluid level good. Fan blade has no movement. Thanks Jimkola!

 

Only when I'm moving and basically at slower speeds? Not idling. I'm off tomorrow I'll jack it up and check my bearings. Thanks QuiGonJon!